1. Field of the Invention
The present invention relates to a multilayered LC composite component and a method for manufacturing the same. More particularly, the present invention relates to improvements in the arrangement of terminal electrodes disposed on the outer surface of the main body of a component.
2. Description of the Related Art
FIG. 13 is a perspective view showing a known multilayered LC composite component 1 related to the present invention. FIG. 14 is a sectional view showing the inner configuration of the multilayered LC composite component 1 shown in FIG. 13.
The multilayered LC composite component 1 includes a rectangular main body 2. The main body 2 includes a pair of side surfaces 3 and 4 facing each other, a pair of end surfaces 5 and 6 facing each other, and an upper surface 7 and a lower surface 8 facing each other.
The main body 2 has a multilayer configuration including a plurality of electrical insulating layers and has capacitor elements 10 and an inductor element 11. In the multilayered LC composite component 1 shown in FIG. 14, one inductor element (L) 11 is disposed between two capacitor elements (C) 10 so as to provide a C-L-C arrangement.
Each of the capacitor elements 10 includes capacitor electrodes 12 on the electrical insulating layers 9. The capacitor electrodes 12 face each other with the electrical insulating layers 9 therebetween so as to define a capacitance.
The inductor element 11 includes a coil conductor 13 on the electrical insulating layers 9. As shown in FIG. 14, the coil conductor 13 includes coil conductive films 14 extending along specific interfaces between the electrical insulating layers 9 and a coil via-hole conductor (not shown) penetrating specific electrical insulating layers 9, and the overall coil conductor 13 defines a helix.
At the center of each of the side surfaces 3 and 4 of the main body 2, ground-side terminal electrodes 16 and 17 are provided, respectively. Also, hot-side terminal electrodes 18 and 19 are disposed on the end surfaces 5 and 6, respectively.
Each of the capacitor electrodes 12 includes ground-side extended portions (not shown) extending to the side surfaces 3 and 4. The ground-side terminal electrodes 16 and 17 are connected to the ground-side extended portions, and accordingly, the inductor element 11 is connected to the ground-side terminal electrodes 16 and 17 via each of the capacitor elements 10 and 11.
Each of the capacitor electrodes 12 includes hot-side extended portions 20 and 21 extending to the end surfaces 5 and 6 of the main body 2. On the other hand, the coil conductor 13 includes coil extended portions 22 and 23 extending to the end surfaces 5 and 6, respectively.
The hot-side terminal electrodes 18 and 19 are connected to the coil extended portions 22 and 23, respectively, so as to be connected to each end of the inductor element 11. Also, hot-side extended portions 20 and 21 are connected to the hot-side terminal electrodes 18 and 19, respectively.
In this way, the multilayered LC composite component 1 shown in FIGS. 13 and 14 constitutes a xcfx80-type LC filer.
The terminal electrodes 16 to 19 are usually formed by applying and baking a conductive paste. However, a process of applying a conductive paste must be performed four times in order to form the terminal electrodes 16 to 19. That is, a first process of applying a conductive paste on one side surface 3 to form the ground-side terminal electrode 16, a second process of applying a conductive paste on the other side surface 4 to form the ground-side terminal electrode 17, a third process of applying a conductive paste on one end surface 5 to form the hot-side terminal electrode 18, and a fourth process of applying a conductive paste on the other end surface 6 to form the hot-side terminal electrode 19 are needed.
In this method, the number of processes of applying a conductive paste increases, and as a result, the cost for manufacturing the multilayered LC composite component 1 increases.
Further, stray capacitance generated between the coil conductor 13 and the terminal electrodes 16 to 19, stray capacitance generated between the capacitor electrodes 12 and the terminal electrodes 16 to 19, and stray capacitance generated between the ground-side terminal electrodes 16 and 17 and the hot-side terminal electrodes 18 and 19 become relatively large. Accordingly, the self-resonance frequency becomes relatively low, which deteriorates the high-frequency characteristics.
In order to overcome the problems described above, preferred embodiments of the present invention provide a multilayered LC composite component and a method for manufacturing the same, having an improved arrangement of terminal electrodes disposed on the outer surface of the main body of a component and in which the number of steps required to form the terminal electrodes is reduced and the stray capacitance problems of the prior art are eliminated.
According to a first preferred embodiment of the present invention, a multilayered LC composite component includes a substantially rectangular main body having a pair of side surfaces facing each other, a pair of end surfaces facing each other, and an upper surface and a lower surface facing each other. The main body has a laminated construction including a plurality of electrical insulating layers and has a capacitor element and an inductor element. The capacitor element includes capacitor electrodes on the electrical insulating layers and the inductor element includes a coil conductor on the electrical insulating layers. Each of the capacitor electrodes includes ground-side extended portions extending to the pair of side surfaces and the coil conductor includes coil extended portions extending to the pair of side surfaces. Each of the side surfaces is provided with a ground-side terminal electrode connected to each of the ground-side extended portions and a plurality of hot-side terminal electrodes connected to the coil extended portions are disposed on both ends of the pair of side surfaces so as to be connected to the end of the inductor element. The pair of end surfaces are provided with end-surface extended portions of the plurality of hot-side terminal electrodes so that at least the approximate center of each of the pair of end surfaces is exposed.
According to a second preferred embodiment of the present invention, a multilayered LC composite component includes a substantially rectangular main body having a pair of side surfaces facing each other, a pair of end surfaces facing each other, and an upper surface and a lower surface facing each other. The main body has a laminated construction including a plurality of electrical insulating layers and has a capacitor element and an inductor element. The capacitor element includes capacitor electrodes on the electrical insulating layers and the inductor element includes a coil conductor on the electrical insulating layers. Each of the capacitor electrodes includes ground-side extended portions extending to the pair of side surfaces and the coil conductor includes coil extended portions extending to the pair of side surfaces. Each of the side surfaces is provided with a ground-side terminal electrode connected to each of the ground-side extended portions and a plurality of hot-side terminal electrodes connected to the coil extended portions are arranged so as to be connected to the end of the inductor element, the plurality of hot-side terminal electrodes being placed on the side surfaces so as to sandwich the ground-side terminal electrodes, and the hot-side terminal electrodes are not disposed on the pair of end surfaces.
Preferably, the coil extended portions include a connecting path for connecting the pair of side surfaces and the connecting path is connected to the remainder of the coil conductor at the middle point of the connecting path in the longitudinal direction.
The ground-side terminal electrodes and the hot-side terminal electrodes may be formed by applying and baking a conductive paste.
Each of the ground-side terminal electrodes and each of the hot-side terminal electrodes may extend in a band-shape on the pair of side surfaces and between the edge line of the upper surface and the edge line of the lower surface and may have extended portions extending to a portion of the upper surface and the lower surface.
In the first preferred embodiment of the present invention, each of the coil extended portions may be arranged so as to reach the side surface and the end surface in the vicinity of the edge where the side surface intersects the end surface.
In order to connect the capacitor element and the inductor element, each of the capacitor electrodes may further include hot-side extended portions to be connected to the hot-side terminal electrodes. Also, the inside of the main body may be provided with a via-hole conductor for connecting the capacitor element and the inductor element.
When each of the capacitor electrodes includes hot-side extended portions to be connected to the hot-side terminal electrodes and when each of the hot-side terminal electrodes includes the end-surface extended portion extending to a portion of the end surface, each of the hot-side extended portions is preferably arranged so as to reach the side surface and the end surface in the vicinity of the edge where the side surface intersects the end surface.
Another preferred embodiment of the present invention provides a method for manufacturing the above-described multilayered LC composite component.
The method for manufacturing the multilayered LC composite component according to another preferred embodiment of the present invention includes the steps of preparing the main body, and simultaneously forming the ground-side terminal electrode and the hot-side terminal electrode on at least one of side surfaces of the main body.
Also, when the manufacturing method according to preferred embodiments of the present invention is applied for manufacturing the multilayered LC composite component in which the coil extended portions and/or hot-side extended portions are formed so as to reach the side surfaces and the end surfaces in the vicinity of the edges where the side surfaces intersect the end surfaces, the manufacturing method preferably includes the steps of preparing the main body, polishing the main body so as to shave off at least edges of the main body, and simultaneously forming the ground-side terminal electrode and the hot-side terminal electrode on at least one of side surfaces of the main body.
Other features, elements, characteristics and advantages of the present invention will become more apparent from the following detailed description of preferred embodiments thereof with reference to the attached drawings.